arch/arm64/include/asm/sparsemem.h

Source file repositories/reference/linux-study-clean/arch/arm64/include/asm/sparsemem.h

File Facts

System
Linux kernel
Corpus path
arch/arm64/include/asm/sparsemem.h
Extension
.h
Size
747 bytes
Lines
33
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef __ASM_SPARSEMEM_H
#define __ASM_SPARSEMEM_H

#include <asm/pgtable-prot.h>

#define MAX_PHYSMEM_BITS		PHYS_MASK_SHIFT
#define MAX_POSSIBLE_PHYSMEM_BITS	(52)

/*
 * Section size must be at least 512MB for 64K base
 * page size config. Otherwise it will be less than
 * MAX_PAGE_ORDER and the build process will fail.
 */
#ifdef CONFIG_ARM64_64K_PAGES
#define SECTION_SIZE_BITS 29

#else

/*
 * Section size must be at least 128MB for 4K base
 * page size config. Otherwise PMD based huge page
 * entries could not be created for vmemmap mappings.
 * 16K follows 4K for simplicity.
 */
#define SECTION_SIZE_BITS 27
#endif /* CONFIG_ARM64_64K_PAGES */

#endif

Annotation

Implementation Notes